Electric appliance



June 30, 1936. w, MCARDLE 2,046,200

' ELECTRIC APPLIANCE Filed Oct. 29, 1934 Patented June so, 1936 UNITED STATES PATENT OFFICE Chicago'Flexible Shaft Company, Chicago, 111.,

a corporation of Illinois Application October 29, 1934, SerialNo. 750,405

3 Claims.

This invention relates to electric appliances of the type having high and low heats such, for example, as in electric stoves, fiatirons, percolators, and the like, and also to electric appliances 5 having plural circuits or plural stage circuits. In this type of electric appliance either a switch or an attachment plug must be manipulated by the user to select one or the other circuit or heating element, as the case may be, according 10 to the condition of use desired at the time.

The present invention has more particular reference to the electrical connector for supplying current to appliances of this type.

One of the objects of the invention is to im- 15 prove electric appliances of this type, particularly in respect to the construction of the electrical connector on the appliance through means of which the user selects one or the other circuit be appreciated by those, skilled in this art as the invention becomes better understood by reference to the following description when considered in 35 connection'with theaccompanying drawing, in which Figure Us a plan view of an electricappliance embodying my invention, with a part broken away to show the electrical connector; 40 Fig. 2 is a diagram of the electric circuit used in this appliance;

Fig. 3 is a vertical'section taken substantially on the section line 3-3 of Figure .1;

Fig. 4 is a fragmentary vertical section taken 45 substantially on the section line 44 of Figure 1, showing the plug connector in position for the high heat; and

Fig. 5 is a similar view showing the plug connector in position for the low heat.

My invention is here shown as applied to a small electric stove of the kind used on a table for heating coffee makers'or percolators, but obviously adapted for other purposes. However, as 55 above stated, the invention may beepplied to other electric appliances for high and low heats or electric circuits for plural stage use.

The appliance shown has a suitable casing, designated generally by 6, within which is carried a block of insulation material I provided on its face with grooves 8 in which are located heating elements in the form of resistance wires. The casing is suitably supported to serve as a portable appliance and in this instance is equipped with a ball 8 having a handle 9 for convenience 10 in moving the appliance when it is heated. 'As a means of economy in cost of manufacture and also to provide for circulation of air, the appliance is formed of two units consisting of a base In and the casing referred to containing the heating elements. The base has a horizontalperforated top H and the c ing- 6 has a perforated bottom |2"provided withl gs l3 struck down and .7 resting on the base part II. The block of insulation material I forming the heating plate rests on a series of brackets l4 formed integral with the sheet metal casing as a continuation of the inwardly and downwardly turned flange ii thereof. A center bolt H holds the heating plate 1, the. casing 6 and the base In in assembled relation, as clearly shown in Fig. 2. 1

Referring to Figure 1, it will be' observed that the bottom plate 12 of the casing is cut away to provide an opening l8 upon the opposed parallel walls of which is supported a cross-bar IQ of insulation material carrying three equally spaced plug-type terminal posts 20, 2| and 22. The bar I9 has a projection 23 at each end fitting in a complemental cut-out in the adjacent wall of the opening I8 so as to locate and hold the bar, as well as the terminal posts, in position and to take the thrust imposed when applying or re.-' moving a plug connector. Each end portion 24 of the bar l9 also overreaches the under side of the bottomplate l2, permitting assembly of the 40 bar from the bottom. These end portions 24 are confined between the plates I I and I2, thus locating the bar vertically.

As shown in Fig. 2, the terminal posts 20 and 2| are connected to the ends of the inner coil 5 25 which provides the low heat and the terminal post 22 is connected to one end of the coil 26, which provides the high heat, the opposite end of the coil 6 being connected to the terminal post 2|.

It will be observed that the terminal posts are equally spaced apart in a common plane so that the attachment plug 21 of a standardcord set may be plugged onto either two adjoining terminal posts. when the attachment plug is placed.

on the center and right hand posts 2! and 22, respectively, the high wattage coil is connected, and when the plug is placed on the center and left hand posts 2| and 20, respectively, the low wattage heating coil is connected. In each such position of the attachment plug, the third terminal post is left exposed and inasmuch as all three tions thereof, and I have also provided a closure 29 shaped to substantially close the open space in front of the exposed terminal post when either set of posts is plugged. In order to effectively use a single closure 29 for both positions, I have arranged it to swing back and forth in the yoke of the casing wall. is effectively accomplished by forming the closure, 29 on the outer end of a link 30 pivotally attached to the center bolt 11 and exposed beneath the post supporting bar IS. The part 29 projects sufliciently so that it may be easily swung laterally from one position to the other, being limited in its movement to each efiective position by striking against the adjacent side wall of the opening 28.

It will be apparent that before the attachment plug may be plugged onto either set of terminal posts, the part 29 must be shifted to one side or the other to permit access of the plug body to the posts and that when this setting is obtained and the attachment plug is applied, the part 29 serves to effectively guard the exposed post and to prevent the user from touching this post accidentally or otherwise.

It will also be apparent that minor changes in the details of construction and arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims, in.- which I claim:

1. In an electric appliance, a casing, electric heating elements within the casing in two circuits providing for high and low heats, said circuits having three coplanar terminal posts the center post of which is common to both circuits,

7 a two-socket plug connector adapted to be 6 plugged onto either two adjoining terminal posts,

" said casing having an opening shaped to permit passage of said plug to either set of terminal posts, said openingleaving the third terminal post exposed when either set of posts is plu 10 and. a guard mounted and. arranged for movement back and forth in the common plane of said terminal posts to close the opening in front of either such third post before the plug may be plugged onto the remaining set of posts. 15

2. An electric appliance comprising a casing having an opening in its outer wall for insertion of an attachment plug, electrical means adapted for plural stage operation and having three terminal posts arranged in a common plane 20 within the casing in alignment with said opening, said terminal posts being spaced apart so that a two-socket attachment plug may be plugged onto either two adjoining posts, and a guard independent of the attachment plug 10- 25 cated in said opening in the casing and movable back and forth in said common plane to close the space in front of each exposed terminal post when a pair of posts is plugged.

3. An electric appliance comprising a casing, heating elements within the casing, a center bolt holding said parts in assembled relation, the casing having an opening in its peripheral wall shaped to receive an attachment plug, three terminal posts mounted in a common plane with- 35 in the casing in alignment with said opening and equally spaced apart so that either two adjoining posts may be plugged by a two-socket attachment plug, and a link pivoted on said center bolt and having a guard at its end disposed in said 40 opening and arranged to be shifted in said common plane from one end of said opening to the other by swinging said link on said center bolt whereby to close the opening in front of either end post when the other two posts are plugged.

MICHAEL W. McARDLE. 

